WHAT, Pokerus? You serious?! You are SO LUCKY. It's so MUCH rarer than shiny pokemon! O_O I had it last time in Emerald, but the save file is gone now.. ;A; Oh, and do remember to put an infected pokemon in the PC if you want to preserve it, or else it will become immune and won't spread the Pokerus to other pokemon. Yes, I believe no cheats were used.
I have White Kyurem, Latias, the Lake Trio, Heatran and Cresselia, but no Keldeo or Genesect as I can't connect to the WiFi.